Unraveling chirality transfer mechanism by structural isomer-derived hydrogen bonding interaction in 2D chiral perovskite

In principle, the induced chirality of hybrid perovskites results from symmetry-breaking within inorganic frameworks. However, the detailed mechanism behind the chirality transfer remains unknown due to the lack of systematic studies. Here, using the structural isomer with different functional group location, we deduce the effect of hydrogen-bonding interaction between two building blocks on the degree of chirality transfer in inorganic frameworks. The effect of asymmetric hydrogen-bonding interaction on chirality transfer was clearly demonstrated by thorough experimental analysis. Systematic studies of crystallography parameters confirm that the different asymmetric hydrogen-bonding interactions derived from different functional group location play a key role in chirality transfer phenomena and the resulting spin-related properties of chiral perovskites. The methodology to control the asymmetry of hydrogen-bonding interaction through the small structural difference of structure isomer cation can provide rational design paradigm for unprecedented spin-related properties of chiral perovskite.

This work synthesized lead halide based chiral perovskite materials with two structural isomers of naphthyl ethylamines. Different stereochemistry of the organic amines contributed to different Hbonding interactions to halides, i.e. numbers and strengths, that further resulted in lattice distortions on the perovskite crystal structures in chiral manner. It was interesting to see the simple change in molecular structure could affect overall chiroptical performances of CD and CPPLs. The logics and interpretations on the experimental results are sound and could contribute to the understanding the molecular designs of ligands for chiral perovskite materials. Therefore, I recommend this article after major revisions. Details are described in following. 1) Introduction. Please include why the chiral perovskite materials are important and what are their advantages for the suggested applications.
2) Figure 1. It is difficult to observe locations and numbers of H-bondings for each cases. It is hard to link the descriptions on the numbers and lengths of H-bondings in the manuscript to the enlarged drawings of Figure 1a, b. Please consider to add other views for clear views on the bonding sites. Also difficult to notice the meaning of the arrows in the Figure. 3) R or S-NEAs have their own chirality. In addition to surface distortions of the lead-halide crystal lattices, is there any possibility that coupling between the dipole moments of the organic ligands and the transition dipoles of the semiconducting perovskite crystals contributes to the chiroptical properties? 4) About the discussions on the surface roughness of the perovskite thin films. As authors indicated, surface roughness could raise apparent CD signals in transmission mode due to contributions of scattering effects from the surface, especially for the CD measurements on the solid materials. However, probably effects of the surface roughnesses are too exaggerated. Diffused reflectance CD (DRCD) may provide more direct evidences for this. 5) Page 10. It is difficult to agree on the Authors descriptions, "the sign conversion phenomena and the different magnitudes of the chiroptic response depending upon the chiral isomer cation can be clearly observed in the CD spectra of morphology-controlled chiral RP OIHP thin film." CD of controlled R-1NEA ( Figure 2e) showed very weak CD signals and totally different to CD of the pure R-1NEA of Figure 2b. It seems that maximum CD peak is inversed with opposite sign and shifted to higher wavelength. Such weak signals and inversions could be observed since the CD are very sensitive and subtle to the molecular structural changes. Please consider to reconsider this part with more elaboration. Probably due to weaker H-bonding interactions and more bulky stereochemistry of 1NEA than 2NEA, addition of 10 mol% may be too much to interfere molecular arrangements and surface distortions than expected. Investigations with samples with additive contents less than 10 mol% are recommended for clear observations on the change of CD spectra. 6) Supplementary Fig.11 does not have absorbance spectra, different to the caption title. Some locations have typo errors in super or subscripts like NH3+.
Reviewer #2 (Remarks to the Author): In this manuscript, using structural isomers with different functional group positions, the author can infer the influence of the hydrogen bond interaction of two isomers on the degree of chiral transfer in the inorganic framework. This is the first time to prove the effect of asymmetric hydrogen bond interaction on chiral transfer. The method of controlling the asymmetry of hydrogen bond interaction through the small structural difference of isomer cations can provide a reasonable design paradigm for the unprecedented spin related properties of chiral perovskite. The manuscript is well written, but there are still some problems to be solved.
1.Although the arrangement of isomers eliminates the influence of components, the position of different functional groups will also bring about the stereo structure effect. How to eliminate this effect?
2.In addition, the research progress of chiral perovskite mixed with A-site alloy introduced by the author is still insufficient, such as J. Phys. Chem. Lett. 2021, 12, 12129. From the CD spectrum, the perovskite composed of the same isomer is different, and the steady-state spectrum should also be different. The reviewer believes that the changes in the three-dimensional structure caused by the same isomer cannot be ignored. Does the author have a more reasonable explanation?
Reviewer #3 (Remarks to the Author): This manuscript reports studies of the chirality transfer by structural isomer-derived hydrogen bonding interaction in 2D chiral perovskites. The presented work and results are sufficiently innovative and noteworthy. These studies could also be quite important for the research field of chiral materials. However, the manuscript can not be published in present form and requires a major revision. The following issues must be addressed.
The materials are anisotropic and have 2D morphology. Therefore, some linear dichroism (LD) studies are necessary as the LD effects can contribute to the chiroptical activity of these materials and this must be taken into account.
There is no proper luminescence studies of the proposed materials except CPPL spectroscopy. There are no ordinary excitation and emission spectra of materials, no luminescent life-times measurements and no any explanation of luminescence mechanisms and their origin in this materials. Without all the presented CPPL results are not clear and irrelevant.
There is no any proper conclusions in the manuscript and no any outlook on the potential applications of the research. Without that the manuscript does not look complete.   R or S-NEAs have their own chirality. In addition to surface distortions of the lead-halide crystal lattices, is there any possibility that coupling between the dipole moments of the organic ligands and the transition dipoles of the semiconducting perovskite crystals contributes to the chiroptical properties?
Author's Response: We appreciate the reviewer for constructive comments regarding the electronic coupling between the two building locks. We understood that reviewer asks us to consider the possible chirality transfer mechanism other than the induced lattice distortion (not surface distortion in our case). In our chiral RP OIHPs system, the chiroptical response (CD and CPPL) is not originated from the R or S-NEA cation exciton transition, but rather associated with the excitonic transition state in lead-bromide framework. As shown in Fig. R3, the R and S-NEA cation itself shows CD response due to their own chirality, which is associated with their

Revision made (colored in blue): (in Page 15~16)
••• The crystallographic study closely matches the experimental results, demonstrating the validity of our proposed mechanism.
It is worth mentioning that the chiral organic molecules have their own chirality and also exhibit CD response. As shown in Supplementary Fig. 18, the chiral organic molecules show mirror image of CD signal at ~ 290 nm depending on their handedness, which is associated with their exciton transition state. However, this transition state is far from the excitonic transition state of chiral RP OIHPs (~ 380 nm), so that the coupling between the dipole moments of the chiral organic molecules (1-NEA or 2-NEA) and the transition dipoles of lead-bromide framework is unlikely to occur. Therefore, it can be concluded that the chiroptical response of our chiral RP OIHPs should be interpreted as a result of induced lattice distortion by the chirality transfer phenomena through the asymmetric hydrogen bonding assisted symmetry breaking rather than electronic coupling between two building blocks. To support our conclusion, the degree of lattice distortion in inorganic framework, which is closely related with the chirality transfer efficiency, can be estimated was investigated by examining

Comment 4:
About the discussions on the surface roughness of the perovskite thin films. As authors indicated, surface roughness could raise apparent CD signals in transmission mode due to contributions of scattering effects from the surface, especially for the CD measurements on the solid materials. However, probably effects of the surface roughnesses are too exaggerated.
Diffused reflectance CD (DRCD) may provide more direct evidences for this.

Author's Response:
We appreciate the reviewer for comments regarding the possible experimental artifact for the CD measurement with solid state thin film. It is well known that organic thin films with large surface roughness can exhibit unexpected CD signal with a strong dependence on the light propagation direction (incident light direction during the CD measurement with solid state thin film) [R11,R12,R13] . The observed optoelectronic behavior stems from the optical interference of thin film's linear birefringence (LB) and linear dichroism (LD) (hereafter LDLB effect), rather than excitonic effects. Therefore, when we investigate the chiroptical activities of thin films with large surface roughness, a basic concept of Mueller matrix analysis is needed to recall; 13 because the observed transmission CD signal (CDobs) is the sum of various contributions, which can be expressed by the equation (1): where the first term refers to genuine CD (CDtrue), while the second term accounts for LDLB effect contribution (the signal of which is taken along an arbitrary axis defined in the laboratory frame in which the prime indicates a 45° axis rotation) [R11] . Many previous studies have reported that significant contribution of LDLB effect can contaminate the true chiroptical response in thin film samples with macroscopic roughness. Therefore, we need to exclude the influence of LDLB contribution to demonstrate the true effect of structural isomer cation on chiroptical activity of chiral RP OIHPs. Since the LDLB effect contribution inverts upon sample flipping (i.e., flipping the sample by 180° with respect to the light propagation axis), the CDtrue and LDLB contribution term can be separately obtained by taking semi-sum and semi-difference of the two CD spectra with different measurement directions, (i.e., front and back).
CD true = 0.5 × (CD obs, front + CD obs, back ) To eliminate the undesirable contamination from the LDLB effect, we have additionally conducted the CD measurement with chiral RP OIHPs thin films by varying the incident light direction. Interestingly, as shown in Fig. R4a and b, both of chiral RP OIHPs thin films without surface morphology control (no MABr added) exhibited the huge CD signal regardless of the light propagation direction (i.e., front and back). However, these huge CD signal almost canceled out upon sample flipping, implying the huge LDLB effect in our chiral RP OIHPs thin films. Furthermore, we isolated CDtrue and LDLB contribution by using equation (2) and (3) to derive the true effect of structural isomer (i.e., sign conversion of CD signal). As shown in CDtrue and g-factor of CDtrue spectra (Fig. R5), the thin film of R-2NEA clearly exhibits sign-inversion behavior near the first extinction band edge (around 375 nm) when compared to R-1NEA. Based on the obtained CDtrue spectra, the effect of the optical anisotropy due to the macroscopic nature can be completely excluded from our experimental results, interpretation, and conclusion.
Furthermore, we have also conducted diffused transmission CD (DTCD) by using integrating sphere as reviewer suggested. During the transmission CD measurement, the intensity of the LCP and RCP at detector can differ due to scattering effects from the surface 14 of thin films. As the integrating sphere can collect all the scattered light, the contribution of light scattering effect on CD signal is excluded (Fig. R6). It is worth noting that LDLB contribution also exists during the DTCD measurement due to the intrinsic asymmetric nature of thin films. Therefore, we conducted sample flipping measurement and isolated the LDLB contribution in the DTCD spectra by using equation (2) and (3) to derive the true DTCD signal (DTCDtrue) of thin films. As expected, the DTCDtrue signal of chiral RP OIHPs thin films (R-1NEA and R-2NEA) showed no noticeable change when the MABr additive was added for surface morphology control (Fig. R7). This result implies that the chiral RP OIHPs thin films did not exhibit circular differential scattering (CDS) behavior at this wavelength region.
Therefore, we can conclude that our observation of the CD signal in the transmission mode does not originate from light scattering due to surface roughness, but from the excitonic transition in the chiral RP OIHP.    (Supplementary; Supplementary Fig. 11 was added) Supplementary Fig. 11. The CD spectra measured under sample flipping condition. The dashed sky-blue and red lines represent the measured CD spectra from front and back side of the films, respectively. The solid orange and purple lines indicate the CDtrue, which is calculated by taking semi-sum.

Comment 5:
Page 10. It is difficult to agree on the Authors descriptions, "the sign conversion phenomena and the different magnitudes of the chiroptic response depending upon the chiral isomer cation can be clearly observed in the CD spectra of morphology-controlled chiral RP OIHP thin film." CD of controlled R-1NEA ( Figure 2e) showed very weak CD signals and totally different to CD of the pure R-1NEA of Figure 2b. It seems that maximum CD peak is inversed with opposite sign and shifted to higher wavelength. Such weak signals and inversions could be observed since the CD are very sensitive and subtle to the molecular structural changes. Please consider to reconsider this part with more elaboration. Probably due to weaker H-bonding interactions and more bulky stereochemistry of 1NEA than 2NEA, addition of 10 mol% may be too much to interfere molecular arrangements and surface distortions than expected.
Investigations with samples with additive contents less than 10 mol% are recommended for clear observations on the change of CD spectra.

Author's Response:
We appreciate the reviewer for constructive and critical comments regarding main concern of our investigation. As reviewer commented, the addition of excess additive may cause an

Revision made (colored in blue):
(in Page 10) ••• As shown in Fig. 2d, the XRD spectra demonstrated that there is no additional impurity phase or secondary phase (MAPbBr3 or PbBr2 etc.) even in the presence of MABr additive.
The UV-visible and steady-state photoluminescence spectra show no shifts in the first excitonic transition (Supplementary Fig.8 and Supplementary Fig.9). In addition, the calculated bandgaps of chiral RP OIHPs are 3.57 eV for R-1NEA and 3.66 eV for R-2NEA obtained from the Tauc plot ( Supplementary Fig.10

Author's Response:
Thank you for the comment. We have checked thoroughly the entire our manuscript in the submitted manuscript and have corrected the mistakes which are not precise or ambiguous statements.

Revision made (colored in blue):
(

<Reviewer 2>
In this manuscript, using structural isomers with different functional group positions, the author can infer the influence of the hydrogen bond interaction of two isomers on the degree of chiral transfer in the inorganic framework. This is the first time to prove the effect of asymmetric hydrogen bond interaction on chiral transfer. The method of controlling the asymmetry of hydrogen bond interaction through the small structural difference of isomer cations can provide a reasonable design paradigm for the unprecedented spin related properties of chiral perovskite.
The manuscript Is well written, but there are still some problems to be solved.

Remark:
We would like to gratefully thank the reviewer for reviewing and evaluating our work. We believe that the reviewer's comments highly improve the quality of our manuscript. Our response to the reviewer's comments can be found below.

Comment 1:
Although the arrangement of isomers eliminates the influence of components, the position of different functional groups will also bring about the stereo structure effect. How to eliminate this effect?

Author's Response:
We appreciate the reviewer's comment. However, it is unnecessary to eliminate the stereo structure effect derived from different functional group locations between 1-NEA and 2-NEA.
The main and core objective of this paper is to elucidate the effect of the stereo structural differences in chiral organic spacer on the overall crystal structure and the associated chiroptical response of chiral RP OIHPs. As expected, the very tiny structural difference between two isomers (different functional group location) can give rise to the huge different stereo structural effect, resulting in completely different three-dimensional (3D) spatial stacking of chiral organic molecules in the lattice of chiral RP OIHPs. Consequently, the different numbers of hydrogen bonding between achiral inorganic framework and chiral spacer are induced depending on the mole"ular'structure of isomer (please refer to Fig. R1 in our response to comment 1 for Reviewer 1).

Comment 2:
In addition, the research progress of chiral perovskite mixed with A-site alloy introduced by the author is still insufficient, such as J. Phys. Chem. Lett. 2021, 12, 12129.
From the CD spectrum, the perovskite composed of the same isomer is different, and the steady-state spectrum should also be different. The reviewer believes that the changes in the three-dimensional structure caused by the same isomer cannot be ignored. Does the author have a more reasonable explanation?

Author's Response:
We appreciate the reviewer's critical comment. We understood that reviewer asks us about the origin of different chiroptical behavior (CD spectra, Fig. 2b

Revision made (colored in blue):
(in Page 10) ••• As shown in Fig. 2d, the XRD spectra demonstrated that there is no additional impurity phase or secondary phase (MAPbBr3 or PbBr2 etc.) even in the presence of MABr additive.
The UV-visible and steady-state photoluminescence spectra show no shifts in the first excitonic transition ( Supplementary Fig.8 and Supplementary Fig.9). In addition, the calculated bandgaps of chiral RP OIHPs are 3.57 eV for R-1NEA and 3.66 eV for R-2NEA obtained from the Tauc plot ( Supplementary Fig.10

CD and CPPL analysis Characterization of Chiroptical and Optical properties
CD and absorbance spectra were analyzed using a J-815 spectrometer (JASCO Corporation).
The baseline was measured in air with a 5 mL/min N2 flow and the scan rate was 200 nm/min with a data pitch of 1 nm. The thin film sample was 2 cm × 1.2 cm, and the coated surface was measured to face the light source. The CPL spectra were analyzed using CPL-300 spectrometer (JASCO Corporation). The scan rate was 100 nm/min with a data pitch of 0.2 nm with 345 nm excitation source. All the spectra were measured under a condition with a maximum DC voltage of ~0.5 V ( Supplementary Fig. 13). The gCPPL value was directly calculated from the instrument program. Steady-state PL spectra were collected with excitation beam wavelength of 350 nm and TRPL spectra were collected with excitation beam of 371 nm (FluoroMax Plus, Horiba, Kyoto, Japan).

<Reviewer 3>
This manuscript reports studies of the chirality transfer by structural isomer-derived hydrogen bonding interaction in 2D chiral perovskites. The presented work and results are sufficiently innovative and noteworthy. These studies could also be quite important for the research field of chiral materials. However, the manuscript cannot be published in present form and requires a major revision. The following issues must be addressed.

Remark:
We would like to gratefully thank the reviewer for reviewing and evaluating our work. We believe that the reviewer's comments highly improve the quality of our manuscript. Our response to the reviewer's comments can be found below.

Comment 1:
The materials are anisotropic and have 2D morphology. Therefore, some linear dichroism (LD) studies are necessary as the LD effects can contribute to the chiroptical activity of these materials and this must be taken into account.

Author's Response:
We appreciate the reviewer's comment. As the reviewer suggested, the observed chiroptical behavior may be exaggerated or contaminated from the optical interference of thin film's linear birefringence (LB) and linear dichroism (LD) (LDLB effect). To eliminate the possibility of undesirable contamination from the LDLB effect, we have additionally conducted the CD measurement with chiral RP OIHPs thin films by varying the incident light direction (i.e., front and back). Diffused transmission CD (DTCD) spectra are also conducted. Please see our response to comment 4 for Reviewer 1.

Comment 2:
There is no proper luminescence studies of the proposed materials except CPPL spectroscopy.
There are no ordinary excitation and emission spectra of materials, no luminescent life-times measurements and no any explanation of luminescence mechanisms and their origin in this materials. Without all the presented CPPL results are not clear and irrelevant.

Author's Response:
We appreciate the reviewer's critical comment. As reviewer suggested, we additionally conducted a series of experiments including ordinary UV-visible absorption spectroscopy, steady-state PL emission spectra, and time-resolved photoluminescence (TRPL) to further investigate the photophysical properties of chiral RP OIHPs. As shown in Fig. R11a, the first excitonic state is clearly observed at 392 nm for 1NEA perovskite and 387 nm for 2NEA perovskite, respectively. The blue shift of first excitonic transition state in 2NEA perovskite is attributed to larger interplanar distance between the inorganic slab (~ 20.1 Å) compared to 19.5 Å for R-1NEA OIHP. In Fig. R10 (in our response to comment 1 for Reviewer 1), the PL emission spectra of chiral RP OIHPs with different structural isomer also show the difference, with Stoke shift of ~ 11 nm. Interestingly, the excitonic peak of the chiral RP OIHPs with 2NEA is sharper and more intense, while chiral RP OIHPs with 1NEA exhibit a broader and weaker excitonic peak. This result implies that the large interplanar distance in chiral RP OIHPs with 2NEA gives rise to the increased dielectric confinement that further facilitates 32 exciton recombination process in the interior lattice. To confirm the luminescence mechanism in chiral RP OIHPs, TRPL spectroscopy is also conducted (Fig. R12). A bi-exponential fitting was used to extract the lifetimes and relevant parameters as presented in Table R1. Both of chiral RP OIHPs have slow lifetime components associated with recombination in the interior lattice in the range of a few nanoseconds (2.068 ns for 1NEA sample and 1.985 ns for 2NEA sample). This reveals that free exciton relaxes very fast due to the large exciton binding energy in 2D chiral RP OIHPs [R17,R18] .
To realize the circularly polarized emission (circularly polarized photoluminescence (CPPL) in our study), a photon emitted from an excitonic transition state should be polarized.
For the CPPL in chiral materials, the slight perturbation of energy state should precede the chirality transfer (Fig. R13). Although a perturbation of energy state associated with chirality transfer can be acquired through a variety of different mechanisms including overall chiral shape; chiral crystal lattice; chiral surface; chiral defect, perhaps the best pathway to obtain CPPL with strong polarization asymmetry is the chiral exciton generated in the chiral crystal lattice. Based on the results of excitation and emission spectroscopy and crystallographic analysis, we can conclude that the observed CPPL in chiral RP OIHPs originate from the chiral exciton generated in the chiral crystal lattice. Due to the different degrees of hydrogen bonding interaction accompanying the different degree of chirality transfer, the strong intensity and polarization asymmetry can be obtained in chiral RP OIHPs with 2-NEA isomer. We gratefully thank the reviewer for helpful comments which significantly improve the quality of our manuscript.   are no longer identical. Therefore, the photon emitted from the chiral OIHPs can be spinpolarized.
complementary phenomena can be exploited to establish the profound information about the electronic structure of chiral RP OIHPs.
Interestingly, As shown in Fig. 3c, the CPPL spectra for the R-1NEA and R-2NEA exhibited CPL emission behavior with completely opposite handedness (Fig. 3c) regardless of the fact that both of 1-and 2-NEA spacer have the same handedness. The asymmetry factors (gCPPL) calculated from the CPPL spectra are 1.89 × 10 -3 for R-1NEA and -2.14 × 10 -3 for R-2NEA (Fig. 3d). This sign conversion phenomena are similar to that observed in the CD spectra at the first extinction band edge (Fig. 2e). To further investigate the photophysical properties of chiral RP OIHPs, we also conducted a series of experiments. As shown in Supplementary   Fig. 8, the first excitonic state is clearly observed 392 nm for 1NEA perovskite and 387 nm for 2NEA perovskite, respectively. The blue shift of first excitonic transition state in 2NEA perovskite is attributed to larger interplanar distance between the inorganic slab (~ 20.1 Å) compared to 19.5 Å for R-1NEA OIHP (Fig. 1). The PL emission spectra of chiral RP OIHPs with different structural isomer also show the difference, with Stoke shifts of ~ 11 nm.
Interestingly, the excitonic peak of the chiral RP OIHPs with 2NEA is sharper and more intense, while chiral RP OIHPs with 1NEA exhibit a broader and weaker excitonic peak. This result implies that the large interplanar distance in chiral RP OIHPs with 2NEA gives rise to the increased dielectric confinement that further facilitates exciton recombination process in the interior lattice. To confirm the luminescence mechanism in chiral RP OIHPs, time-resolved photoluminescence (TRPL) spectroscopy is also conducted ( Supplementary Fig. 13). A biexponential fitting was used to extract the lifetimes and relevant parameters were presented in Table S4. Both of chiral RP OIHPs have slow lifetime components associated with recombination in the lattice interior in the range of a few nanoseconds (2.068 ns for 1NEA sample and 1.985 ns for 2NEA sample). This reveals that free exciton relaxes very fast due to the large exciton binding energy in 2D chiral RP OIHPs 7,46 .
To realize the CPPL in chiral materials, a photon emitted from an excitonic transition state should be polarized. For the CPPL in chiral materials, the slight perturbation of energy state should be preceded by the chirality transfer ( Supplementary Fig. 14). Although a perturbation of energy state associated with chirality transfer can be acquired through a variety of different mechanisms including overall chiral shape; chiral crystal lattice; chiral surface; chiral defect, erhaps the best pathway to obtain CPPL with strong polarization asymmetry is the chiral exciton that can be generated in the chiral crystal lattice. Based on the results of excitation and emission spectroscopy and crystallographic analysis, we can conclude that the observed CPPL in chiral RP OIHPs originate from the chiral exciton generated in the chiral crystal lattice. In line with the results of CD spectra, the CPPL result also implies that the modulating the hydrogen-bonding interaction between the chiral molecules and inorganic frameworks can facilitate the chirality transfer but also modulate the electronic structure of chiral RP OIHPs, which is consistent with our previous theoretical expectation 20 .  There is no any proper conclusions in the manuscript and no any outlook on the potential applications of the research. Without that the manuscript does not look complete.

Author's Response:
We appreciate the reviewer's critical comment of future application. The core object of this paper is to scrutinize the effect of different structural isomer configurations on chiroptical response in chiral RP OIHPs and to present the material design rule for developing new-type of semiconductor with excellent intrinsic chirality and stability. However, as reviewer suggested, it is also important to explore the potential application of this research. Therefore, as a proof-of-concept, planar-type circularly polarized light-photodetectors (CPL-PDs) based on chiral RP OIHPs was additionally demonstrated. Fig. R14 describes the structure of CPL-PDs as well as experimental procedures to investigate its discriminating capability between LCP and RCP illumination. Fig. R15 represents the photocurrent vs. time curve of CPL-PDs with different isomer under LCP and RCP illumination by using laser at 365nm, 385 nm, and 400 nm. Both of CPL-PDs exhibited reliable operational stability and distinguishability upon repeated illumination measurement. Fig. R16 shows the photocurrent vs. voltage curve of CPL-PDs with different isomer under LCP and RCP illumination by using the same laser at the applied external voltage range from -4 V to 4 V. It is worth noting that CPL-PDs based on R-2NEA exhibited higher photocurrent response to LCP than RCP (Fig. R17), whereas CPL-PDs based R-1NEA showed better response to RCP than LCP over entire voltage range, which is consistent with the observed result of CD spectra at the first extinction band edge. Although the current level of our proof-of-concept CPL-PDs is limited to a few of pA level, we clearly demonstrated that the sign conversion phenomenon in CD spectra can be also recognized as a different preferential photocurrent response of CPL-PDs. We expect that important application and enhanced performance can be developed based on our preliminary observation and proposed material design rule.

Fig. R14. Schematic illustration of proof-of-concept planar type CPL-PDs application.
The channel between neighboring electrodes had a length of 70 μm. The light was generated by LED and lasers with various wavelengths of 365 nm, 385 nm, and 400 nm. The unpolarized light was converted to circularly polarized light by using linear polarizer and quarter-waveplate (Thorlabs, LPVISA050).

Revision made (colored in blue):
(in Page 16-17) ••• (as well as more asymmetric hydrogen-bonding interaction) induced by structural isomer with different functional group location.
As a proof-of-concept, planar-type circularly polarized light-photodetectors (CPL-PDs) based on chiral RP OIHPs was demonstrated. Supplementary Fig. 20 describes the structure of CPL-PDs as well as experimental procedures to investigate its capability to discriminate between LCP and RCP illumination. The photocurrent vs time curve of CPL-PDs with different isomers under LCP and RCP illumination by using laser at 365nm, 385 nm, and 400 nm were presented in Supplementary Fig. 21. Both of CPL-PDs exhibited reliable operational stability and distinguishability upon repeated illumination measurement. In addition, the photocurrent vs voltage curve of CPL-PDs with different isomer under LCP and RCP illumination by using the same laser applying external voltage range from -4 V to 4 V were also provided ( Supplementary Fig. 22). It is worth noting that in CPL-PDs based on R-2NEA always exhibited higher photocurrent response to LCP than RCP ( Supplementary Fig. 23), whereas CPL-PDs based R-1NEA showed better response to RCP than LCP over entire voltage range, which is consistent with the observed result of CD spectra at the first extinction band edge.
Although the current level of our proof-of-concept CPL-PDs is limited to a few of pA level, we clearly demonstrated that the sign conversion phenomenon in CD spectra can be also recognized as a different preferential photocurrent response of CPL-PDs.
Finally, we carried out a thermal stability test to compare the influence of the chiral isomer cation on the structural integrity of chiral RP OIHPs. Both chiral RP OIHPs with chiral NEA isomer cations showed excellent stability under ambient atmosphere after six weeks, •••
Furthermore, we also demonstrated that the sign conversion phenomenon in CD spectra can be converted in a different preferential photocurrent response of CPL-PDs. Moreover, 2NEA chiral RP OIHPs also demonstrated exceptional environmental stability under harsh conditions (75 °C and 75% RH) for seven days. Our results suggest that small conformational changes in isomers (such as different locations of functional groups) can lead to greatly differing spinrelated and structural properties of chiral RP OIHPs. Our proposed strategy based on structural isomer chiral cations clarifies the relationship between hydrogen-bonding interactions and chiroptical phenomena in chiral RP OIHPs. Eventually, it could provide a pathway toward establishing the material design rules for developing novel chiral 2D OIHPs with strong intrinsic chirality and stability, which is essential for chiro-optoelectronic applications such as CPL detectors or emitters. We expect that important applications and next-generation energy conversion devices with excellent performance may be developed based on our preliminary observations and proposed material design rule.